S1970 Empiric Antibiotic Use With Rescue Infliximab Does Not Improve Outcomes in Acute Severe Ulcerative Colitis: A Retrospective Cohort Study

Introduction: Acute Severe Ulcerative Colitis (ASUC) can be life-threatening and may result in poor outcomes. Approximately 30–50% of patients fail to respond to initial corticosteroid treatment and infliximab is often used as rescue therapy. In clinical settings, antibiotics are sometimes empirically administered with infliximab, though evidence supporting improved outcomes is lacking. We evaluated the impact of concurrent antibiotic use with infliximab in ASUC. Methods: A retrospective cohort study was conducted using the TriNetX platform. International Classification of Diseases-10 code K51, procedure codes, visit diagnosis codes, and keywords such as “antibiotics” and “infliximab” were used to identify eligible patients from 01/01/2013 to 12/31/2022. We compared 2 cohorts. 1: Patients who received infliximab on or within one day of admission and antibiotics on or within one day after infliximab administration (n = 1,341). 2: Patients who received infliximab on or within one day of admission but did not receive antibiotics within 3 days after infliximab administration (n = 1,447). Propensity score matching was performed for baseline characteristics. Primary outcome was all-cause mortality. Secondary outcomes included IBD-related surgery, ICU care, emergency department (ED) utilization, and sepsis. Results: A total of 1,028 patients out of 2,788 met criteria and were included in the analysis. Males formed the majority (51.5% in Cohort 1, 53.3% in Cohort 2); mean age was 40 years in both groups. A total of 10 deaths occurred in each group (risk difference = 0; OR = 1.0). 39 patients in Cohort 1 vs 29 in Cohort 2 developed sepsis (risk difference = 0.973%; OR = 1.3; 95% CI: 0.833–2.214). Conclusion: Mucosal injury in ASUC may lead to bacterial translocation, with increased risk of sepsis. This has prompted empiric antibiotic use in clinical practice. There was no difference in mortality or major outcomes between patients who did and did not receive antibiotics with infliximab. Antibiotic use was not associated with reduced sepsis risk and may contribute to higher healthcare costs and antimicrobial resistance. These results highlight the importance of antimicrobial stewardship and the need for further prospective studies.